Yes, do be careful, I punched a hole through my stomach. I was on the maximum dosage. I took it from the age of forty for arthritis, and it is wonderful, but one day I thought I was having a heart attack. Ulcers and liver damage - which is fine. I took Omeprazole until my liver was fine again. My movements are severely limited now during the winter, and I put on loads of weight. I'm still trying to work out whether I should be permanently on medication or whether I can manage as I am, but the arthritis is not only in my hips (which they won't replace until I am 60) but in my hands and feet and starting to be in my knees. I think I shall carry on just taking the odd ibuprofen or two on particularly busy days for as long as I can.
I think it was partly my own fault, you are meant to take it after food. I was finding it hard to sleep at night, to get comfortable, so I used to take it with just a glass of milk before bed. I don't think milk was enough to coat my stomach properly. However, it did take a whole ten years for me to get to that state.